Can't turn autocalculate back on.

Hi guys, I am really new to vba. I managed to piece together the below macro but I can't seem to get autocalculate to turn back on and would appreciate some help.

Sub testing()
Application.Calculation = xlCalculationManual
Dim FilesToOpen
   Dim x As Integer
   On Error GoTo ErrHandler
   Application.ScreenUpdating = False
   FilesToOpen = Application.GetOpenFilename _
     (FileFilter:="Microsoft Excel Files (*.xls), *.xls", _
     MultiSelect:=True, Title:="Select Short Term")

   If TypeName(FilesToOpen) = "Boolean" Then
       MsgBox "No Files were selected"
       GoTo ExitHandler
   End If
  x = 1
  Dim wkb As Workbook
  Dim wks As Worksheet
  Application.DisplayAlerts = False
  While x <= UBound(FilesToOpen)
      Set wkb = Workbooks.Open(FilesToOpen(x))
      On Error Resume Next
      On Error GoTo ErrHandler
      Cells.Copy
        ThisWorkbook.Activate
        Sheets("Short Term").Activate
        Range("A1").Select
        ActiveSheet.Paste
         wkb.Close False
      x = x + 1
  Wend
  Application.DisplayAlerts = True

   FilesToOpen = Application.GetOpenFilename _
     (FileFilter:="Microsoft Excel Files (*.xls), *.xls", _
     MultiSelect:=True, Title:="Select Term")
   If TypeName(FilesToOpen) = "Boolean" Then
       MsgBox "No Files were selected"
       GoTo ExitHandler
   End If
  x = 1
    Application.DisplayAlerts = False
  While x <= UBound(FilesToOpen)
      Set wkb = Workbooks.Open(FilesToOpen(x))
      On Error Resume Next
      On Error GoTo ErrHandler
      Cells.Copy
        ThisWorkbook.Activate
        Sheets("term").Activate
        Range("A1").Select
        ActiveSheet.Paste
         wkb.Close False
      x = x + 1
  Wend
  Application.DisplayAlerts = True
   FilesToOpen = Application.GetOpenFilename _
     (FileFilter:="Microsoft Excel Files (*.xls), *.xls", _
     MultiSelect:=True, Title:="Select GSE-TLGP")
   If TypeName(FilesToOpen) = "Boolean" Then
       MsgBox "No Files were selected"
       GoTo ExitHandler
   End If
  x = 1
    Application.DisplayAlerts = False
  While x <= UBound(FilesToOpen)
      Set wkb = Workbooks.Open(FilesToOpen(x))
      On Error Resume Next
      On Error GoTo ErrHandler
      Cells.Copy
        ThisWorkbook.Activate
        Sheets("GSE-TLGP").Activate
        Range("A1").Select
        ActiveSheet.Paste
         wkb.Close False
      x = x + 1
      Wend
rename

Application.DisplayAlerts = True
ExitHandler:

   Application.ScreenUpdating = True
   Exit Sub
ErrHandler:
   MsgBox Err.Description
   Resume ExitHandler

     On Error GoTo ErrHandler


End Sub